National Dental Assisting Examining Board (NDAEB) Practice Exam

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Prepare for the National Dental Assisting Exam with comprehensive quiz questions, including multiple choice and detailed explanations. Equip yourself for success!

Each practice test/flash card set has 50 randomly selected questions from a bank of over 500. You'll get a new set of questions each time!

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What effect does adding more water during the mixing of gypsum have on the study model?

  1. It becomes denser

  2. It becomes weaker

  3. It sets faster

  4. It remains unchanged

The correct answer is: It becomes weaker

When more water is added during the mixing of gypsum for a study model, the resulting mixture becomes weaker. This occurs because the excess water alters the composition of the gypsum, leading to a lower overall density and strength of the final product. Gypsum, when mixed with the appropriate amount of water, forms a strong physical structure as the crystals of calcium sulfate dihydrate bond properly. However, adding too much water dilutes this mixture, preventing the crystals from forming as tightly together and leading to a more porous and less robust model. The excess water creates gaps and weak points in the structure, which compromises the integrity and stability of the model. Understanding the correct water-to-gypsum ratio is crucial for achieving a strong and durable study model, which is essential for effective diagnostics and treatment planning in dentistry.